Thread-changing device in embroidery machines



G. SIEBER.

THREAD CHANGING DEVICE IN EMBROIDERY MACHINES.

APPLICATION FILED SEPT- 22, I921.

Patented July 18, 1922.

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GrOlTW'AL'l SIEBER, 0F PLAUEN, SAXONY.

THREAD-GHANGING DEVICE IN EMBROIDERY MACHINES.

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Specification of Letters Patent. 7

Patented July 18, 1&22.

Application filed September 22, 1921. Serial No. 502,463.

T 0 all whom it may concern:

stance in embroiderywith various colours.

In former devices for the same purpose the thread removed from the needles was cut oil from the needle-point to the thread tensioning roller and then used as waste. In recent devices the remaining thread-ends are rewound upon the thread-rollers for the purpose of saving yarn, and although this requires much time and is very troublesome, it is of advantage inpreventing waste. In order to wind up the thread-ends as quickly as possibl experiments have been made to drive the thread-rollers themselves as a whole and thereby effect the unwinding of the thread placed around the thread tensioning roller. When using spools of equal thickness this was easily accomplisl'ied without causing the yarn to tear during operation of unwinding.

But, if the spools which are driven at the same speed are of different diameter, the tension exerted on the thread between the tension roller and spool will vary with. the different spool-sections. In consequence thereof the thread with a too great tension must tear, so that the object of preventing waste wi i not be attained.

The present invention enables uniform unwinding of the yarn from the thread tensioning roller in spite oi unequal diameter of the latter. This is attained by simultaneously driving both the thread tensioning roller and the winding device, to wit, the device for driving the spools. The spools are arranged on and frictionally engaged with positively driven rods. Now it is impossible for the large spool even owing to its larger diameter to unwind more yarn than a smaller'neighbouring spool, as the thread stretched between spool and thread tensioning roller will keep the spool, engaged with the spool-rod only by little fric- 'tion, so long in its position till the friction between spool and spool-rod will cause the latter to rotate the spool. This will be the case just, as soon asthe spools of smaller diameter have drawn up the difference in thread. Thus owing to the frictional connection between the spools and rods automatic compensation takes place during the winding operation in spite of the positive drive between thread tensioning roller and spool-rod.

In the accompanying drawing the invention is shown in a diagrammatical way.

Fig. 1 is a cross-section and Fig. 2 the corresponding top plan view.

On a shaft 1 extending the whole length of the embroidery machine a thread spool carrier 2 is rotatably arranged adapted to be fixed in the position required by means of a locking mechanism 3 of any suitable construction. Provided on the carrier 2-are spools 4-, 4, st, for threads 01" diiierent kind or colour. Fixed to the shaft 1 is a driving means, for instance a chain-wheel 5, which by way of chain 9, is in communication with another chain-wheel 8 arranged on the shaft 1 6 01": the thread tensioning roller 7-. The chain-wheel 8 preferably is provided with a crank 10 and can he axially moved on the shaft 6, for the purpose of coupling and uncoupling. With this end in view the hub 51.1 of the chain-wheel Sis provided with coupling-teeth 12 engaging corresponding recesses in the hub of the thread tcnsioning roller 14:.

Each of the thread-spools 4, 4L, l is arranged on a rod 15 provided at its lower part with a disk 16 on which the weight of the thread-spool rests. The spool-rods 15 and disks 16 are positively driven from. the shaft 1 through gears 17, 18 fixed on said rods and meshing with intermediate gears 19 which in their turn through bevel gears 20, 21 are driven from tho sh aft 1. Of course this driving mechanism may be of any suitable construction, and that shown in the drawing is solely one embodiment of my invention.

The operation of the device is as follows As soon as the moment of thread-changing has arrived the embroidery threads are cut off close to the surface of the fabric and removed from the needles. 7 Then the chainwheel 8 is coupled to the thread tensioning roller 7 by axial displacement and the roller 7 and with it the shaft'l are turned in. the direction of Y the arrow Thereby the rods 15 are also rotated and take the spools 4, 4 along through'friction. Consequently the spools need not exert the shown in Fig. l.

slightest force for unwinding the thread from the thread tensioning roller, as thelatter delivers the thread itself.

Of course the spools of small diameter will take up the thread coming from the thread tensioning roller in a much slower manner than those of greater diameter. Consequently as soon as the thread freed from the thread tensioning roller is used up, the spools of large diameter will slip upon their rods 15 or on the disks 16, respectively, owing to the tension exerted on the thread. This slipping will continue till further thread is unwound from the tensioning roller.

IVhen all thread-ends are wound up the crank 10 is again released, and the wheel 8 and thread tensioning roller are uncoupled through the medium of a spring. Then the lock 3 is withdrawn, and other thread rollers are brought to operation by suitably turning the thread roller carrier.

Having now fully described my invention I declare that what I claim is 1. In a thread. changing device for embroidery machines, the combination of thread spools, carriers for said spools, means for driving said spools, a thread tensioning roller and means forjointly driving said spool-carriers and thread tensioning roller, substantially as described.

2. In a thread changing device for embroidery machines, the combination of a spool carrier, spools rotatably arranged on said carrier, of means for mechanically driving said spools, a thread tensioning roller and means for jointly. driving said spoolcarriers and thread tensioning roller, substantially as described.

3. In an. embroidery machine, the combination with a thread tension roller, of spools for threads and means for simultaneously driving said tension roller and spools so that the latter will rewind the threads when out OK at their ends.

4. In an embroidery machine, the combination with a thread tension roller, of an adjustable carrier, spools supported thereon, and means for simultaneously driving said spools and tension roller so as to cause said spools to rewind the threads when out off at their ends and means for holding said carrier in adjusted position. i

5. In anembroidery machine, the combi nation with a thread tension roller, of a ca 1- rier, spools rotatively supported on said carrier and means for simultaneously driving said spools and tension roller so as to cause said spools to rewind the thread when out off at their ends.

6. In an embroidery machine, the combi nation with a tension roller, a tnrnable car rier, sets of spools rotatively supported on said carrier so that the several sets may be used one at a time and means for positively driving simultaneously said tension roller and the operative set of spools so as to -cause the threads to be rewound on said spools when cut off at their ends.

7. In an embroidery machine, the combination with a tension roller, a polygonal carrier and shaft on which said carrier is turnably supported, sets of spools rotatively sup ported on said carrier, one set on each face thereof, means for locking said-carrier in adjusted position and means for simultaneously driving said tension roller and a set. of spools so as to cause the threads when out off at their ends to be rewound onto said operative set of the spools.

8. In an embroidery machine, the combination with a tension roller, av carrier, spindles rotatively supported on said carrier, spools mounted on and frictionally engaged with said rods and means for driving said tension roller and said spindles so that the spools will be caused to rewind the threads when cut off at their ends.

9. In an embroidery machine, the combination with a tension roller, oi spools, rotary means yieldingly supporting said spools and means for simultaneously driving said tension roller and said first named means sothat the spools will be caused to rewind the threads when out off at their ends.

In testimony whereof I ttfllX mysignature in presence of two witnesses.

G-OT'IWALT SIEBER. Witnesses:

JosErH Minna, RUDo E. ,FRIOKE. 

